Elevated Levels of Intelectin-1, a Pathogen-binding Lectin, in the BAL Fluid of Patients with Chronic Eosinophilic Pneumonia and Hypersensitivity Pneumonitis

OBJECTIVE: Human intelectin-1 (hITLN-1) binds to galactofuranosyl residues, which are present in the microbial cell wall, but which are absent in mammalian tissues, and has been suggested to play an immunological role against microorganisms. However, the involvement of hITLN-1 in the pathogenesis of diffuse pulmonary diseases remains unknown. The aim of this study was to compare the hITLN-1 concentrations in the bronchoalveolar lavage (BAL) fluid of patients with diffuse pulmonary diseases. METHODS: The cell components and concentrations of hITLN-1 were analyzed in the BAL fluid of 8 patients with idiopathic chronic eosinophilic pneumonia (ICEP), 3 patients with drug-induced eosinophilic pneumonia, 4 patients with hypersensitivity pneumonitis (HP), 11 patients with sarcoidosis, 9 patients with cryptogenic organizing pneumonia, and 5 patients with idiopathic fibrosing interstitial pneumonia (fibrosing nonspecific interstitial pneumonia or usual interstitial pneumonia). RESULTS: The hITLN-1 concentrations in the BAL fluid of patients with ICEP and HP were higher than in those with other diseases. In the ICEP group, no significant difference was observed in the hITLN-1 concentrations of patients with or without a history of bronchial asthma. CONCLUSION: The results of the present study suggest that hITLN-1 may be involved in the pathogenesis of ICEP and HP, and that an increase in the hITLN-1 concentration in the BAL fluid may represent a new biomarker for these diseases.